This presentation includes two real life experiences that explains how phylogenetic analyses can immensely help epidemiology and healthcare.

1. Phylogeny and UsPhylogeny and Us
By
Priyankar Sen, Ph.D.,
Assistant Professor, CBST,
VIT University, Vellore.

2. CASE 1CASE 1: Kimberly Bergalis: Kimberly Bergalis

3. •First known case of clinically-transmitted HIV
•Who was one of six patients purportedly infected with HIV by
dentist David Acer, who had AIDS.
•In December 1987, dentist Dr. David Acer removed two of
Bergalis's molars. Acer was HIV-positive at the time, having been
diagnosed that fall.
•In March 1989 Bergalis began to show symptoms of AIDS and was
diagnosed with the disease in January 1990.
• The Center for Disease Control (CDC) initial report that she had
likely acquired her infection from her dentist prompted Acer to
write an open letter requesting that his patients be tested for HIV
infection.
•The Florida health and rehabilitation service tested over 1000
patients, discovering two additional HIV-positive patients. The
CDC would eventually identify a total of ten HIV-positive former
Acer patients, and link the infections of six to their dentist.

5. CASE 2CASE 2: SARS 2002-03: SARS 2002-03

6. INTRODUCTION
• SARS (Severe Acute Respiratory Syndrome) is
a disease caused by a new type of coronavirus
(SARS-CoV).
• It consists of a 29,571 base-long, single-
stranded RNA and displays a characteristic
spiky envelope protein that resembles a
crown.

7. palm civet is
believed to be
the source of
the human
SARS-CoV

8. nucleotide sequences of 13 strains of human SARS coronaviruses
for which the location and the date of collection were known
GenbankAccession CollectionDate Location
________________ ______________ ____________________
'AY278489' 'DEC-16-2002' 'GZ 12/16/02'
'AY394997' 'DEC-26-2002' 'ZS 12/26/02'
'AY395004' 'JAN-04-2003' 'ZS 01/04/03'
'AY394978' 'JAN-24-2003' 'GZ 01/24/03'
'AY394983' 'JAN-31-2003' 'GZ Hospital'
'AY304495' 'FEB-18-2002' 'GZ 02/18/03'
'AY278554' 'FEB-21-2003' 'Metropole 02/21/03'
'AY278741' 'FEB-26-2003' 'Hanoi 02/26/03'
'AY274119' 'FEB-27-2003' 'Toronto 02/27/03'
'AY283794' 'MAR-01-2003' 'Singapore 03/01/03'
'AY291451' 'MAR-08-2003' 'Taiwan 03/08/03'
'AY345986' 'MAR-19-2003' 'Hong Kong 03/19/03'
'AY394999' 'MAY-15-2003' 'Hong Kong 05/15/03'
'AY627048' ' ' 'Palm civet'
•The sequences correspond to the spike S protein, which is responsible for binding to
specific receptors and is considered a major antigenic determinant.
Guangzhou and Zhongshan,
labelled as GZ and ZS
respectively

9. QUESTIONS
1. CAN PHYLOGENETIC ANALYSIS TELLS ABOUT
THE SOURCE AND DYNAMICS OF AN EPIDEMIC?
2. DO IT ABLE TO TELL ABOUT THE EXACT
LOCATION/PLACE FROM WHERE THE EPIDEMIC
HAS SPREADED?
3. CAN IT TELL ABOUT THE EXACT DATE OF THE
OUTBURST?
THE ANSWER IS……………………..YES!!!

10. PAIR-WISE DISTANCES (SPIKE PROTEIN nt sequences)

13. Not convinced enough?...........

14. ON WHICH DATE IT HAS STARTED???
With the help of Kimura’s Model that considers different rate of
transition and transversion…..

15. END
RESULT

16. SUMMARY
 The first cases of SARS appeared in late 2002 in the Chinese
province of Guangdong.
 It grew into a major outbreak in the next few months (January
through February 2003).
 The majority of the infected individuals acquired the disease in the
Guangzhou Hospital.
 A doctor who had worked in this hospital traveled to Hong Kong in
February 2003 and stayed at the Metropole Hotel.
 The doctor and a number of other hotel guests all became infected
with the virus and traveled to different destinations (Vietnam,
Canada, Singapore, Taiwan) carrying the disease and the virus.

17. REFERENCES:
1. https://en.wikipedia.org/wiki/Kimberly_Bergalis
2. http://in.mathworks.com/help/bioinfo/examples/reconstru
cting-the-origin-and-the-diffusion-of-the-sars-epidemic.html
3. http://www.people.com/people/archive/article/0,,2011338
1,00.html
4. Centre for disease control and prevention (CDC).

18. THINK!!!....
1. What we can do in our country……..???
2. Can we think for a entrepreneurship or
socio-preneurship…………????